/*
 * Created on 2005-6-17
 * Made In YeQiangWei 
 * 
 */
package com.yeqiangwei.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
//import javax.servlet.UnavailableException;

public class SetCharacterEncodingFilter implements Filter {
    protected String encoding = null;
    protected FilterConfig filterConfig = null;
    protected boolean ignore = true; /* 忽略 */
  
    
    public void init(FilterConfig filterConfig) throws ServletException {
        this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
        String value = filterConfig.getInitParameter("ignoer");
        if(value==null)
            this.ignore=true;
        else if(value.equalsIgnoreCase("true"))
            this.ignore=true;
        else if(value.equalsIgnoreCase("yes"))
            this.ignore=true;
        else
            this.ignore = false;
       
    }


    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) 
    					throws IOException, ServletException {
        if(this.ignore||(request.getCharacterEncoding()==null)){
            String encoding = selectEncoding(request);
            if(encoding!=null)
                request.setCharacterEncoding(encoding);
        }
        chain.doFilter(request,response);
    }

    public void destroy() {
        this.encoding = null;
        this.filterConfig = null;
 
    }
    protected String selectEncoding(ServletRequest request) {
        return this.encoding;
    }
}
